The main structure of a crutch basically consists of 4 pieces: 3 straight circular section tubes, where one of the tubes performs the function of the leg, and the other two tubes joined to the first perform the function of handle and arm support and are joined to the straight tube by a T-shaped piece, to which the leg and the arm support form a determined angle.
The definition of leg and arm for elbow crutches, according to European Standard EN ISO 11334-1:2007 and its Spanish equivalent UNE-EN ISO 11334-1, are described as:                Arm: Part of the crutch that is above the rear reference point of the handgrip.        Leg: Part of the crutch that is below the rear reference point of the handgrip.        Handgrip: Part of the crutch envisaged by the manufacturer to be gripped by the hand when the crutch is used.        Handle: Part of the crutch where the handgrip is attached.        Rear reference point of the handgrip: Point next to the rear position limit where the length of the handle ends        
With a double adjustment system, the leg and arm length settings are done in steps by way of springs which fit into holes found in the structure of the leg and arm support. The adjustment of the leg is performed using a telescopic mechanism whose length is fixed using a system of bolts with springs which fit into the holes found along the length of the tubes which form the telescope.
A simple design type consists of an adjustable telescopic leg and a piece which performs the functions of arm-support, handle and cuff. In this design, the arm is not adjustable and is referred to as leg adjustable only.
Other special designs exist in which the crutch is not adjustable, in order to reduce weight and favour user comfort.
All these known designs result in a range of crutches which each weigh between 500 g and 1000 g.
Furthermore, the current standard on elbow crutches specifies the minimum safety requisites to which the design and production must comply, without taking into account important factors related to user comfort.
The current user of crutches either habitual or sporadic, often has to pick up the crutch from the floor after simple tasks such as opening a door; an operation that is both uncomfortable and extremely difficult for older people or those with back problems.
In addition to the problems of stability mentioned, such as constant dropping on the floor, crutches hitherto known are heavy and difficult to manage.
Other difficulties presented by current crutches are related to the materials employed in their production. As they are made from metallic materials, they are heavy and susceptible to corrosion and deterioration and, as a result, degrade over time causing irritating noises when used.
Other problems presented by crutches currently found on the market is the relationship of the adjustment of the cuff, which is done by steps, which is to say rather inadequate and cannot be carried out continuously, being a mechanism where the position selection is performed by springs which deteriorate and add more noise during use.
There are ultra light crutches (composite or titanium) which need to be tailor made in the factory to meet the requirements of the end user as they cannot be adjusted in any way once they reach the user.
One known crutch type is that disclosed in patent U.S. H2138H, in which the crutch is described as carbon made with three interconnected graphite/epoxy tubes upon which a handle and a cuff is permanently fixed, with no possibility of undertaking any adjustments to the position and fixing of the handle and the cuff on the arm.
As a result, the object of this invention is to develop a crutch such as that which is described below, which overcomes the problems described, so as to prevent it from falling to the floor, so that it is not too heavy, so that user comfort is improved in as far as use and handling are concerned, so that it does not deteriorate at such a fast rate as those we are familiar with up to now, so that continuous adjustment is possible and not by jumps or steps, and ultimately so that it is adaptable to all the possible physical characteristics of the user and that the cost is relatively low.